This Training Grant Program (TGP) provides interdisciplinary research training in mechanistic toxicology with applications to human disease prevention. Support is requested for 6 predoctoral and 2 postdoctoral positions. Qualified applicants must demonstrate motivation for careers in toxicology research. Predoctoral applicants must have excellent backgrounds in biological and physical sciences and mathematics. Postdoctoral fellows must have the Ph.D., M.D., DVM, or other appropriate doctoral degree. The TGP is based in the Department of Environmental Health Sciences (EHS), which has a distinguished history of graduate training in toxicology. The curriculum provides a rigorous academic foundation for predoctoral students in basic biomedical sciences, biostatistics, epidemiology, and mechanistic toxicology. Interactions among Program participants occur through core courses, weekly seminars, dissertation committees, collaborative research, and an annual research symposium. Trainees complete independent research projects that illuminate a mechanistic basis for environmental determinants of disease. The TGP faculty has an exemplary record of funding, publications, training, and leadership in scientific societies and panels. Mentors include those with laboratories equipped for contemporary research training from the molecular to the organismal level. In addition, mentors in human exposure assessment, biomarker development, and environmental epidemiology provide opportunities for trainees to do translational research relating exposures to human health. Trainees publish their work in peer-reviewed scientific journals and are prepared for ultimate leadership positions in academia, industry, and government. A Steering Committee advises the Director and Associate Director on the budget, operating procedures, selection, and continuing review of trainees and mentors. An external Review Board reviews the TGP annually to make recommendations for continual improvement. Consultants provide advice about minority recruiting and applications of research to human populations. The University of Michigan furnishes a premier multidisciplinary research environment for training modern toxicologists. Strong institutional support for the TGP is contributed by the Department of EHS, School of Public Health, and the Rackham School of Graduate Studies, enriching the external support provided by NIEHS and ensuring an effective Training Program.